Grinding-mill.



No. 874,244. I PATENTED DEC. 17, 1907.

' H. 0. ROBINSON.

GRINDING MILL. APPLIOATION FILED r33. 2a. 1907.

702%ze6ge5 Elven Z0 2" THE NOkRIS PETER ssssssssssssssssss c HARRY O.ROBINSON, OF MUNOY, PENNSYLVANIA.

GRINDING-MILL.

Specification of Letters Patent.

Patented Dec. 17', 1907'.

Application filed February Z3, 1907- Serial No. 358,880.

To all whom it may concern:

Be it known that I, HARRY C. ROBINSON, a citizen of the United States,residing at Muncy, in the county of Lycoming and State of Pennsylvania,have invented new and useful Improvements in Grinding-Mills, of whichthe following is a specification.

This invention relates to grinding mills.

I do not limit the use of the invention to any particular type of mill,but find it, how-. ever, of especial utility when incorporated in one ofthe class known as disk or attrition mills. Mills of this particularclass involve two vertically disposed disks set face to face or arrangedin parallelism and generally 0ppositely rotative. One of these disksusually has an eye through which the stock to be ground is fed into thespace between the two disks. This disk which has the eye also has withinthe eye a hub and arms projecting rom the hub and joined with the wallof the eye, it being the custom to make the body of the disk, the hub,and arms or spokes integral. It is the practice to so shape these armsthat they aid in positively feedin the material to the two disks. Oneway of oing this is to have the side faces of the respective armsangular and converging inwardly so that, when the disk equipped withsuch arms is rotated, the latter act to force the stock into said space,no matter in which direction the said disk rotates. These arms and thewall of the eye, as well as other points on the. disk, when the latteris in action, are subjected to an unusual amount of wear. The grainwears the edges of the arms round, and also forms pockets, cavities, orrecesses in the arms, in the wall of the eye, and at other places, andthese round edged arms and recesses, cavities, or pockets are so shapedas not only to retard the proper feed of the stock to the grinding area,but as to absolutely feed a large portion of the material backward.

It is primarily the object of my invention to provide a disk having aneye and of such a construction that the feed of the stock will not beobstructed or retarded to any extent. I prefer to provide a disk ofsubstantially familiar construction having the usual eye through whichthe material may pass, and I combine with this disk, means forpreventing wear on said arms and wall, and this means is of such anature that, when worn by the action of the grain or other material, itmay be separated bodily or as an entirety from the disk and replaced bya new and perfect device. This insures a great saving, for, with the olddisks, when the same were worn as I have pointed out, it was necessarynot only to wholly replace the same, but to replace the shafts whichcarried them, for the parts were generally permanently connectedtogether, so that, when. the disk was discarded, the supporting shafttherefore was valueless for further use in the grinding mill, in that itcould not be separated from the disk.

In the drawings accompanying and forming a part of this specification Ishow in detail one form of embodiment of the invention, which, to enablethose skilled in the art to practice the invention, will be hereinafterfully set forth, while the novelty of said invention will be included inthe claims succeeding said description.

Referring to said drawings: Figure 1 is a face view of a grinding diskincluding my invention. Fig. 2 is a sectional view of said disk. Figs. 3and 4 are detail view of the shield or guard shown in the precedingfigures and viewing the same from opposite sides thereof.

Like reference characters indicate like parts throughout the severalfigures.

As hereinbefore indicated, I do not limit myself to the incorporation ofmy improvements in any particular type of mill, although they are ofespecial utility when employed in connection with an attrition or diskmill. These attrition or disk mills take several different forms, as iswell known, and I may readily adapt the invention to any of these.

In the drawings, I have shown one of the disks of an attrition or diskmill, the same being denoted in a general way by 2 and having therein aneye, as 3, through which the material to be ground by the disk 2 and thecompanion disk (not shown) is fed. It is customary to set these disksvertically. Within this eye is ordinarily disposed a hub, as 4, fromwhich extend several arms or spokes 5. The hub, arms, and disk may beand generally are integral, and may be formed by casting. This, however,is not essential. The hub 4L and arms 5 constitute the customary supportfor the disk 2, and

this hub may be fastened to its shaft in any desirable way. For example,the hub may be shrunk on said shaft. This, however, is immaterial.

With disks of the ordinary kind, the stock is passed through the eye 3from a hopper not shown, and it is usually the practice to make the arms5 of wedge shape, this being accomplished by forming the sides of thearms upon angles which converge inward, these angular faces serving toaid in feeding the stock into the space between the two disks. The arms5 unite with the wall of the eye 3 and at such places, and along thearms particularly on the edge thereof, and even upon the hub 4 thematerial wears so that the surfaces thus acted upon soon become abradedor pocketed, and these abraded or worn away portions frequently takesuch shapes or forms as not only to check the proper supply of materialto the space between the disks, but actually cause a very large portionof the material to be fed backward, ruinously reducing the capacity ofthe mill, and causing the feed spout and other exposed parts to berapidly worn away.

To prolong the life of the disk 2 by preventing this wear, I provide ashield or guard, as that denoted in a general way by 6. This shield, inthe present instance, is of such a nature as to protect not only thearms 5 and wall of the eye 3 from wear,-but also thehub 4. The disk 2,hub 4, and arms 5 may be in expensively made by casting from iron, whilethe shield 6 may consist of cast steel, and is removably or separablyassociated with the disk, so that the shield, and not the usuallyexposed parts of the disk, receives the abrasion of the material. Whensaid shield is worn away, it can be quickly taken from the disk byseparating the same from the companion disk, and a new and uninjured oneput in its place without the necessity of discarding the disk havingsuch shield. The character of the shield will, of course, vary inaccordance with the particular construction ofdisk, the shieldillustrated in the drawings being of such a nature as to adapt itprimarily to the disk represented. The shield 6 in the present case iscomposed of a hub, as 7, arms, as 8, and a rim, as 9. While notessential, I prefer to make these parts in one piece, so that the shieldas an entirety can be separated from the disk. This shield may be heldin assembled relation with the disk in any desirable way, although Ihave shown and will hereinafter describe one advantageous mode ofobtaining this result. The hub 7 is of a form to cover or inclose thehub 4, and this form, in the present case, is a chambered or casing one.The shape of the hub, however, is of no consequence; in fact, it is notimperative that it be employed, although its presence is advantageousduring the casting of the shield, in that the hub prevents the arms 8from springing or breaking away from the rim 9. The spokes or arms 8 areof channel form, to cover or inclose the spokes 5, their sides embracingsaid spokes 5. The rim 9 covers the wall of the eye 3.

I may tap into the inner surface of the disk 2 several screws, as 10,the heads of which engage over the marginal portion of the shield 6 tohold said shield removably in place. In the present case I do not relywholly on these screws 10 for this purpose The segments 11 which arebolted or other wise suitably fastened to the inner surface of the disk2, and which constitute the working portion of the said disk, overlie,at their inner edges, the shield 6, and thus aid the screws 10 inmaintaining the shield 6 in position. Therefore, should any one of thescrews 10 become accidently loosened, the shield 6 cannot be dislodged,for it would be held solidly in position by the segments 11. IVhen theshield 6 becomes worn from con stant use, it can be readily dismountedby taking off the segments 11 and removing the screws 10, followingwhich a new shield can be put in place of the old worn one. I prefer tomake the sides of the spokes or arms 8 angular and have these angularfaces converge inwardly, so as to force the material into the spacebetween the disk 2 and the cooperating disk which, as previously setforth, is not shown.

As will be obvious, the hub 4 and arms or spokes 5 present a spider, andthis spider constitutes, in the present case, a main or supportingspider, an auxiliary spider being provided by the hub 7 and the arms orspokes 8. This second spider is, as will be obvious, removable. Theauxiliary spider is shown as having as a part thereof the rim 9, so thatsaid auxiliary spider with its rim can be bodily separated from thedisk. In some cases this auxiliary spider with its rim may accomplish.all that the main spider does.

What I claim is:

1. A grinding mill disk having an eye, a

hub in the eye, and arms extending from the hub to the wall of the eyecombined with a shield removably associated with said disk and coveringsaid arms and wall.

2. The combination of a grinding mill disk having an eye, a hub in theeye, and arms extending from the hub to the wall of the eye, and ashield removably associated with the disk and covering the hub, arms,and wall.

3. A grinding mill disk having an eye, a hub surrounded by the wall ofthe eye, and arms extending from said hub to the body of the disk,combined with a shield consisting of a hub, arms, and a rim, the hub andarms of the shield being adapted to fit the first mentioned hub andarms, and the rim of the shield being adapted to cover said wall, saidshield being removably associated with the disk, and the arms of saidshield having their side faces angular and convergingtoward the innerface of the disk.

4. As an article of manufacture, a shield comprising a hub, armsextending from the hub, and a rim united with the arms, the hub being ofchambered form and the arms being of channel form.

5. As an article of manufacture, a shield comprising a hub, armsextending from the hub, and a rim united with the arms, the hub being ofchambered form and the arms being of channel form, said arms havingangular converging faces.

6. A grinding mill disk having an eye combined with a shield providedwith a rim rese ments on one of its side faces, an eye, a

in the eye, and arms extending from the hub to the wall of the eye,combined with a shield covering said arms and wall and engaged by saidsegments.

In testimony whereof I have hereunto set my hand in presence of twosubscribing wit nesses.

HARRY O. ROBINSON.

Witnesses:

G. L. PAINTER, GEO. A. BARDORFF.

